Solid-state silicon anode with extremely high initial coulombic efficiency
Solid-state silicon anode with extremely high initial coulombic efficiency
复制标题
具有极高初始库伦效率的固态硅阳极
DOI：
10.1039/d2ee04057c
复制
发表时间：
2023
影响因子：
32.5
通讯作者：
Han, Fudong
中科院分区：
文献类型：
--
作者：
Huang, Yonglin;Shao, Bowen;Wang, Yan;Han, Fudong
硅被认为是固态电池（SSB）的重要阳极材料，因为它在解决与锂金属阳极相关的关键挑战（例如枝晶形成和形态不稳定性）方面具有独特的性能。尽管之前关于固态硅负极的报道取得了许多令人兴奋的结果，但初始库仑效率（ICE）这一表征第一次循环电化学可逆性并直接影响电池能量密度的关键参数尚未得到充分考虑。在这里，我们研究了硅和三种代表性固体电解质（SE）之间的电化学稳定性，包括典型的硫化物（75Li2S-25P2S5，LPS）、碘化物取代的硫化物（70（0.75Li2S-0.25P2S5）-60LiI，LPSI）和氢化物基SE（3LiBH4-LiI，LBHI），以提高固态硅的ICE阳极。结合第一性原理计算、电化学测量、异位 XPS 表征和机械测量，我们报告说，与硫化物基 SE 相比，LBHI 的硅阳极表现出优异的电化学和化学稳定性，从而实现了高性能固态硅阳极，其 ICE 在迄今为止报道的所有硅阳极中创下了 96.2% 的新高。具有硅阳极的 LBHI 的优异稳定性也在具有富镍层状氧化物阴极的固态全电池中得到了证明。该研究为开发实际应用的高性能硅阳极提供了新的见解。
Silicon is considered an important anode material for solid-state batteries (SSBs) because of its unique properties in addressing key challenges associated with Li metal anodes such as dendrite formation and morphological instability. Despite many exciting results from previous reports on solid-state Si anodes, the initial Coulombic efficiency (ICE), a critical parameter that characterizes the electrochemical reversibility for the first cycle and directly influences the energy density of the battery, has not been well considered. Here we study the electrochemical stability between Si and three representative solid electrolytes (SEs), including a typical sulfide (75Li2S-25P2S5, LPS), an iodide-substituted sulfide (70(0.75Li2S-0.25P2S5)-60LiI, LPSI), and a hydride-based SE (3LiBH4-LiI, LBHI), to improve the ICE of solid-state Si anodes. Combining first-principles computations, electrochemical measurements, ex situ XPS characterizations, and mechanical measurements, we report that LBHI demonstrates superior electrochemical and chemical stability with Si anodes compared with sulfide-based SEs, enabling a high-performance solid-state Si anode with a record high ICE of 96.2% among all Si anodes reported to date. The excellent stability of LBHI with Si anode was also demonstrated in solid-state full cells with nickel-rich layered oxide cathodes. The research provides novel insights into developing high-performance Si anodes for practical applications.